Dear candidate as you know M.Sc Tech Geophysics is a course with lot of potential offered by Banaras Hindu University. However your rank is 91, I would say your chances are not that strong, but yes if seats remain vacant, then your seat will be ensured. Keep on following the Waiting list upgradation, if it freezes for around 1 month, then expect that there would not be more upgradation. By the time don't rely only on one Institute, try to apply into different colleges for better possibilities of admission.

Hope you make your chance!!!

Good luck!!